The present invention relates to a thermistor and, more particularly, to a thermistor utilizing a thin, uniform temperature sensitive layer of silicon carbide deposited on a suitable substrate by sputtering.
Conventional thermistors are now available in the form of beads, rods, discs or flakes, however, because of their particular construction, all exhibit an insufficient responsive to change in ambient temperature.
Conventional thermistors, operable at elevated temperatures, typically employ a temperature sensitive layer comprising as a principal component, either alumina or silicon carbide. The deficiencies of such thermistors are as follows.
The conventional high temperature sensing thermistors utilizing alumina are problematic with regard to stability. The conventional silicon carbide high temperature sensing thermistor utilizing silicon carbide as either a single crystal or a polycrystalline body thereof, are superior to devices using alumina in terms of stability but normally need a long time for the response and are difficult and expensive to manufacture. Such devices are disclosed, for example, in Landis et al., U.S. Pat. No. 3,339,164 or Van der Beck, U.S. Pat. No. 2,916,460.